Conformal TIM for RF?

[mtwieg]

Hello, I want to add a heatsink to some swithmode RF PAs I've been building, and to do so I'll need to use an electrically insulating conformal thermal interface material between the components and heatsink. This is because the components in need of heatsinking are of various sizes (like between 0603 and 1008 SMT footprints) and are very close together, so they present a very uneven topography. I'm looking for a non-adhesive TIM pad (not a potting compound or curing putty, I want it to be removable) which won't affect the electrical performance of the circuitry, but none of the TIMs I've seen mention anything about loss tangent (but they do mention relative permittivity, which I presume will have some effect). Are there any popular TIMs for use in RFPAs which are conformal and electrically insulated? My operating frequency is around 100MHz.

 

[FvM]

As far as I'm aware of, Berquist has the largest portfolio of thermal gap fillers and similar materials. https://www.bergquistcompany.com/thermal_materials/index.htm

I've used it for power electronics only and didn't see RF related data yet. Maybe you should contact Bergquist sales.